Function createLoaderElement

src/service/loader-element.js:28–53

(
  ampDoc,
  element,
  elementWidth,
  elementHeight,
  startTime = ampDoc.win.Date.now()
)

 * @return {!Element} The loader root element.
 */
export function createLoaderElement(
  ampDoc,
  element,
  elementWidth,
  elementHeight,
  startTime = ampDoc.win.Date.now()
) {
  // We create the loader root element up front, since it is needed
  // synchronously. We create the actual element with animations when the
  // service is ready.
  const loaderRoot = element.ownerDocument.createElement('div');

  getLoaderServicePromise(ampDoc, element).then((loaderService) => {
    const endTime = ampDoc.win.Date.now();
    const initDelay = endTime - startTime;
    loaderService.initializeLoader(
      element,
      loaderRoot,
      initDelay,
      elementWidth,
      elementHeight
    );
  });

  return loaderRoot;
}